A captain is a leader responsible for a ship, aircraft, sports team, or military unit.

On a ship, the captain makes all major decisions: choosing the route, responding to storms, and ensuring the crew's safety. Even today, a ship's captain has legal authority over everything that happens aboard. In aviation, the captain sits in the cockpit's left seat and has final responsibility for the aircraft and everyone on it.

In sports, team captains lead by example and help coordinate their teammates. A soccer team captain might call the coin toss before a game and encourage teammates when they're behind. Unlike a ship's captain, who holds absolute authority, a team captain leads through respect and hard work rather than rank.

Military captains command smaller units like companies of soldiers. A captain in the army ranks above lieutenants but below majors, typically leading 100 to 200 soldiers.

You might also hear someone called the “captain of industry” when they lead a major business, or students might elect a team captain for an academic competition. The word always suggests someone who takes responsibility, makes decisions under pressure, and looks out for the people counting on them.